@jaimemlg, I don't think so.
I think, the difference between the 2 lamp designs I could see, is regarding air flow.
If you look at the lamps front side, you can see a kind of funnel next to the reflector with the bulb. That's for cooling; air is coming from the JVC's fan, flowing through this funnel to cool down the bulb.
Now I've seen 2 different lamp designs:
The one, where is nothing mounted inside this funnel, and the other, where this funnel was equipped with a tin sheet metal + kind of a baffle.
Both factory new X70's I've had were equipped with the lamp w/o this metal.
The lamp design with metal I could only see, because JVC service had provided me a new lamp as replacement part for my 1st X70 regarding the pulsing issue in high lamp mode. But it hasn't solve this, so I returned the 1st X70. However, my 2th X70 is also affected. Now I do not ask for the other lamp design cause I know, it will not change anything in this case.
Regarding the sheet metal with the baffle I guess, that's for the projector's upside down mounting and a special airflow; because for what this baffle otherwise could be?
An other thought - maybe the metal equipped "funnel" results in a better cooling so the bulbs brightness get's more stability? I don't know for sure.
I really would like to know, what's the correct lamp design for our JVC's!
Maybe the lamp w/o metal+baffle is the special one, cause if I look closer at the pictures I've done for comparison, the lamp w/o metal also has the little noses for catching such a sheet metal ...
X70_lamp_designs.zip 498.6259765625k . file
X70_lamp_compartment.zip 119.123046875k . file